In an interview with Empire Magazine he said: "Certain things we were doing a little reflexively. Some of the humour was getting a bit glib.

"One of the hardest things to notice is when your new idea has become your old idea and it’s time to get rid of it.”

Capaldi has already said that audiences will be seeing a something with "a bit more gravity."

“Some situations are more sombre and I think there are more rooted dramatic scenes. Over the past two or three years, which I’ve loved, there has often been a breathless vigour; we still have that attack, but we have another level of drama, another tone. And the scenes are longer.”

The Doctor's sidekick Clara, played by Jenna Coleman, agrees that audiences can expect a darker feel to the show.

She told Empire: "It’s amazing how different it feels."

"It’s darker. The limits feel like they’re being pushed more in terms of the danger and the dread. It’s scarier, that’s for sure.

“A producer once told me this is the hardest job because you’re creating characters and telling stories while always on the run. But Steven’s changed the format quite a lot. We have much longer scenes now.”

The series premiere of Doctor Who, series eight, will air on August 23, and is entitled "Deep Breath".

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